The provision of a thermal insulating sleeve at the nozzle body of a fuel injection valve is already known from German Patent No. 30 00 061 C2. A flange of the thermal insulating sleeve is inserted in an interior groove of the fuel injection valve and is sealed against the mounting hole of the cylinder head by a sealing ring. At the injection end, the thermal insulating sleeve has a ring-shaped collar bent toward the interior on which an elastic thermal insulating ring is supported. The thermal insulating ring is arranged between the injection end of the nozzle body of the fuel injection valve and the ring-shaped inwardly bent collar of the thermal insulating sleeve.
In a fuel injection nozzle known from British Patent No. 759 524, a pliable thermal insulating element, inserted as a disk-shaped thermal insulating ring between a face of the nozzle body and a collar of a tension nut, is formed from a thermal insulating material. To protect the inner side of the thermal insulating ring not covered by the collar or by the nozzle body from the corrosion by the combustion gases, this inner side is edged with a ring with a U-shaped cross section formed from a thin metal sheet.
A drawback of the thermal insulating sleeve according to the definition of the species is that it requires a relatively great assembly expenditure since the thermal insulating sleeve must be pre-assembled on the fuel injection valve. In addition, an additional sealing ring is necessary to seal the mounting hole of the cylinder head from combustion gases, resulting in an increase in the manufacturing and assembly effort and not least in costs. Dissipation of the heat, which develops in the nozzle body as a result of the combustion of the internal combustion engine, across the thermal insulating sleeve to the cylinder head is possible in the known configuration of the thermal insulating sleeve only to a limited extent.